1 Corinthians 9:2

9:2 If I am not an apostle to others, at least I am to you, for you are the confirming sign ¹  of my apostleship in the Lord.

1 Corinthians 9:27

9:27 Instead I subdue my body and make it my slave, so that after preaching to others I myself will not be disqualified.

1 Corinthians 14:19

14:19 but in the church I want to speak five words with my mind to instruct others, rather than ten thousand words in a tongue.

[9:2]  ¹ tn Grk “the seal.”